You may have different experiences at the passport-control and customs sections depending on the laws of the country you are visiting as well as the type of items you are bringing in.
Passport official: Good morning. Can I see your passport?
Passenger: Here you are
Passport official: Thank you very much. Are you a tourist or here on business?
Passenger: I'm a tourist
Passport official: That's fine. Have a pleasant stay
Passenger: Thank you
Customs official: Good morning. Do you have anything to declare?
Passenger: I'm not sure. I have two bottles of whiskey. Do I need to declare that?
Customs official: No, you can have up to 2 quarts
Passenger: Great
Customs official: Have you brought any food into the country?
Passenger: Just some cheese I bought in France
Customs official: I'm afraid I'll have to take that
Passenger: Why? It's just some cheese
Customs official: Unfortunately, you are not allowed to bring cheese into the country. I'm sorry